1. Physics 1 – Nov 15, 2016 P3 Challenge –
When an object is moving on an incline you should rotate your axes to align with the incline.
What are a) the parallel and b) the perpendicular components of weight when using a rotated frame of reference?
Today’s Objective: Friction on an incline sample problem – HMK review
Get out the “Multibodies etc…” worksheet HMK for check.

2. Agenda, Assignment IB 2.2 Forces Assignment: Agenda
Friction on an incline
Assignment:
Two remaining Problems on “Multibodies and Inclines”
Agenda
Friction on Incline Sample Problem
Review of 3 homework problems – led by each third of the class.

3. Motion on an incline with friction methods
If the motion of the body of interest is moving up or down an incline, rotate your axes.
This makes the net force perpendicular to the incline = 0.
Weight gets split into two components
W = mg sinθ directed down the slope
W⊥ = mg cosθ directed into the incline
Fnet, = Up the slope – down the slope = ma
Fnet,⊥ = ⊥ to the slope – into the slope = 0 ( the reason you want to rotate axes)

4. Friction on incline Sample Problem
What will happen to a 15.0 kg block initially at rest on an incline if the coefficient of static friction between the block and the incline is 0.22 and the coefficient of dynamic friction is 0.18?

5. Exit Slip - Assignment
A block is launched up an incline. Indicate the direction and type of friction for each of it’s phases of motion if it moves up the slope a distance to come to rest sitting on the slope.
What’s Due on Thurs Nov 17? (Pending assignments to complete.)
Multibody and Inclines Worksheet, #4 and 5
What’s Next? (How to prepare for the next day)
Read p57-75